A5013873343- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Semiconductor Quantum Structures and Devices
- Optical Network Technologies
- Optical Coatings and Gratings
- Molecular Junctions and Nanostructures
- Neural Networks and Reservoir Computing
- Photonic Crystals and Applications
- Semiconductor materials and devices
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Semiconductor Detectors and Materials
- Pulsed Power Technology Applications
- Semiconductor materials and interfaces
- Strong Light-Matter Interactions
- Laser-Plasma Interactions and Diagnostics
- Laser Design and Applications
- Advanced optical system design
- Clinical Laboratory Practices and Quality Control
- Chalcogenide Semiconductor Thin Films
- GaN-based semiconductor devices and materials
- Electronic and Structural Properties of Oxides
- Neural Networks and Applications
- Advanced Fiber Laser Technologies
- Silicon Carbide Semiconductor Technologies
- Plasmonic and Surface Plasmon Research
Technische Universität Berlin
2016-2025
Georgia Institute of Technology
2019
Sandia National Laboratories
1989-2018
Lodz University of Technology
2016
Institute of Physics
2016
Vertically Integrated Systems (Germany)
2010-2012
n&k Technology (United States)
2004-2011
U.S. Air Force Institute of Technology
1997-2006
Sandia National Laboratories California
1990-2005
Samsung (South Korea)
2002
The Coomassie Brilliant Blue G-250 method for protein in urine has been evaluated analytical accuracy and clinical applicability. Extremely simple to perform, the test exhibits good precision sensitivity. color developed per gram of is protein-type dependent, so no single standard completely satisfactory. Color intensity linearly related concentration up 1500 mg/L when used with a manual bichromatic method. Accuracy was clinically acceptable patients variety protein-losing diseases, having...
Abstract Neural networks are one of the disruptive computing concepts our time. However, they fundamentally differ from classical, algorithmic computing. These differences result in equally fundamental, severe and relevant challenges for neural network using current substrates. urge parallelism across entire processor a co-location memory arithmetic, i.e. beyond von Neumann architectures. Parallelism particular made photonics highly promising platform, yet until now scalable integratable...
Abstract Many bosons can occupy a single quantum state without limit. It is described by the quantum-mechanical Bose–Einstein statistic, which allows condensation at low temperatures and high particle densities. Photons, historically first considered bosonic gas, were late to show this phenomenon, observed in rhodamine-filled microcavities doped fibre cavities. These findings have raised question of whether also common other laser systems with potential technological applications. Here we...
We have conducted a series of experiments designed to measure the flashover strength various azimuthally symmetric $45\ifmmode^\circ\else\textdegree\fi{}$ vacuum-insulator configurations. The principal objective was identify configuration with greater than that standard design, which consists polymethyl-methacrylate (PMMA) insulator between flat electrodes. thickness $d$ and circumference $C$ insulators tested were held constant at 4.318 95.74 cm, respectively. peak voltage applied ranged...
Single-emitter vertical-cavity surface-emitting lasers (VCSELs) and multiple-emitter VCSEL arrays designed for emission at 980 nm, with large oxide aperture diameters (φ) from ~10.5 to 33.5 μm φ of ~7.5 that are configured in three-emitter seven-emitter electrically parallel triangular hexagonal arrays, respectively, have record bandwidths optical output powers VCSELs such cumulative emitting areas. We demonstrate room temperature (RT) maximum small-signal modulation (f <sub...
We present experiments on reservoir computing (RC) using a network of vertical-cavity surface-emitting lasers (VCSELs) that we diffractively couple via an external cavity. Our optical computer consists 24 physical VCSEL nodes. evaluate the system's memory and solve 2-bit XOR task 3-bit header recognition (HR) with bit error ratios (BERs) below 1\,\% digital-to-analog conversion (DAC) root-mean-square (RMSE) 0.067.
We achieve the continuous-wave (CW) lasing of electrically-injected, first-of-their-kind vertical-cavity surface-emitting lasers (VCSELs) that use a subwavelength monolithic high-refractive-index-contrast grating (MHCG) mirror. The MHCG, unlike well-known (HCG) is neither membrane suspended in air nor structure requires cladding layer. MHCG patterned semiconductor material atop VCSEL cavity creating an all-semiconductor laser. Static measurements show CW operation VCSELs from room...
In this Letter a fully vectorial numerical model is used to search for the construction parameters of monolithic high-contrast grating (MHCG) mirrors providing maximal power reflectance. We determine design highly reflecting MHCG where etching depth stripes less than two wavelengths in free space. analyze MHCGs broad range real refractive index values corresponding most common optoelectronic materials use today. Our results comprise complete image possible mirror constructions potential...
Brain-inspired computing concepts like artificial neural networks have become promising alternatives to classical von Neumann computer architectures. Photonic target the realizations of neurons, network connections and potentially learning in photonic substrates. Here, we report development a nanophotonic hardware platform fast energy-efficient neurons via arrays high-quality vertical cavity surface emitting lasers (VCSELs). The developed $5\times5$ VCSEL provide high optical injection...
Artificial neural networks have become a staple computing technique in many fields. Yet, they present fundamental differences with classical hardware the way process information. Photonic implementations of network architectures potentially offer advantages over their electronic counterparts terms speed, processing parallelism, scalability and energy efficiency. Scalable high performance photonic (PNNs) been demonstrated, yet remain scarce. In this work, we study such scalable, fully...
Abstract Vertical cavity surface emitting lasers (VCSELs) are high performance quality and low cost light sources in many optoelectronic components. Polarization stable single mode (SM) emission over a large spectral bandwidth at ambient temperatures is an important prerequisite for applications such as microscale atomic clocks, gas sensing, optical coherence tomography, interconnects. At the same time, it to maintain simple robust VCSEL device design concept. A hybrid monolithic index...
Abstract The problem of proficiency evaluation clinical chemistry laboratories is considered in terms the accuracy, precision, and allowable limits error 10 common analytical procedures, individual analysts occurrence gross laboratory mistakes. concept operational chart developed, its use illustrated. Operational charts summarize basic quality-control information a clear, concise, goal-oriented perspective which useful for evaluating performance comparing groups laboratories. aid identifying...
A 6.1-MV, 0.79-MA laser-triggered gas switch (LTGS) is used to synchronize the 36 modules of $Z$ machine at Sandia National Laboratories. Each module includes one switch, which serves as last command-fired module, and hence determine time each electrically closes relative other modules. The $\ensuremath{\sim}81\mathrm{\text{\ensuremath{-}}}\mathrm{cm}$ in length, $\ensuremath{\sim}45\mathrm{\text{\ensuremath{-}}}\mathrm{cm}$ diameter, immersed mineral oil. outer envelope consists six...
The dependence of the photoluminescent properties In0.48(AlyGa1−y)0.52P alloys (0≤y≤0.5) on growth temperature and substrate misorientation off GaAs(100) has been studied. Samples were grown using low-pressure metalorganic vapor phase epitaxy. By studying ordering behavior in InGaP as a function simultaneously, very large range low-temperature photoluminescence emission energy—135 meV—has obtained. linewidth exhibits strong, continuous extent atomic (the energy) alloys. results indicate that...
We have developed a statistical model for the flashover of $45\ifmmode^\circ\else\textdegree\fi{}$ vacuum-insulator interface (such as would be found in an accelerator) subject to pulsed electric field. The assumes that initiation plasma is stochastic process, characteristic component delay time much greater than formative time, and average rate at which flashovers occur power-law function instantaneous value Under these conditions, we find probability given by...
We have developed an empirical electrical-breakdown relation that can be used to design large-area water-insulated pulsed-power systems. Such systems often form integral part of multiterawatt accelerators, and may incorporated in future petawatt-class machines. find complete dielectric failure is likely occur water between a significantly field-enhanced anode less-enhanced cathode when...
Creatine kinase (CK, EC 2.7.3.2) activity in the serum of a patient with metastatic carcinoma migrated as two distinct bands cathodal to origin and CK-3 on agarose gel electrophoresis. The more isoenzyme (CKm-2) is high molecular mass, precipitated by ammonium sulfate at 30% saturation, not retarded Sephadex G-100. Treatment urea concentration 6 mol/L caused CKm-2 elute proteins lower mass G-100 column shifted electrophoretic migration position just (CKm-1). Antibody CK-1 CK-2 did affect...
The Z pulsed power driver at Sandia National Laboratories is used for a variety of high energy physics experiments. system stores 20 megajoules the present nominal ±85 kV Marx charge voltage. consists 36 basically identical modules, each with DC-charged generator, water insulated intermediate store capacitor, laser triggered gas switch, and pulse-forming section. High current drivers such as are able to create densities per cubic centimeter in ~1 cm <sup...
In this letter, we propose and numerically investigate a new vertical-cavity surface-emitting laser (VCSEL) structure consisting of nearly lambda-thick active optical cavity sandwiched between two planar monolithic subwavelength high-index-contrast gratings (MHCGs) etched directly into the semiconductor layers surrounding cavity. The allows reduction vertical thickness subsequent MHCG VCSEL to roughly 0.6 μm for emission at 980 nm. Compared with conventional all-semiconductor distributed...
We produce experimental 980 nm vertical cavity surface emitting lasers (VCSELs) with a wide range of oxide aperture diameters (ø) from ∼2.5 to 15 µm on wafers designed minimize the epitaxial growth and VCSEL design complexity. The structures are grown in batches 12, 3-inch diameter production metal-organic vapor phase epitaxy machine. characterize top VCSELs at room temperature (∼25 °C) – grouped into unit cells 16 rows columns—using an automated (university-built) wafer mapping system,...
Dilute nitride (DN) vertical cavity surface emitting lasers (VCSELs) near 1300 nm exhibit state-of-the-art performance including bandwidths of 10 GHz and a record high error-free data transmission 12 Gbps. Renewed interest in DN VCSELs stems from emerging applications kilometer-reach digital communication across optical fiber free space via eye safe beams, time-of-flight structured light sensing, photonic-electronic integrated circuit interconnects. We produce VCSEL wafers production...